public class code053 {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		int i = 1;
		int sum = 0;
		while (i <= 50) {
			if (i % 7 == 0)
				sum = sum + i;
			i++;
		}
		System.out.println(sum);
	}

}
